Container stopper

ABSTRACT

A container stopper comprising a compressible body ( 2 ) having at least one end for insertion into an opening of a container, and a film ( 1 ) on the end of the compressible body ( 2 ) for providing a protective layer between the compressible body and the container contents; wherein at least a region at the end of the compressible body has at least one property whereby upon compression of the body for insertion into an opening of a container said region compresses without substantially adversely affecting the protective layer provided by the film ( 1 ).

FIELD OF THE INVENTION

[0001] The present invention relates to improved stoppers for stopperingopenings in containers. In particular, the present invention relates toimprovements to container stoppers that have a film on at least one endto protect the stopper from the contents of the container the stopper isutilised in. The stoppers of the invention are particularly useful asstoppers for openings in containers of fluids such as wine. Theinvention also relates to an improved method of producing containerstoppers such as the container stoppers of the invention and packagedproducts, particularly packaged fluid products, in which a stopper ofthe invention is incorporated.

BACKGROUND OF THE INVENTION

[0002] A number of products are packaged in containers where theopenings in the container are stoppered. In these circumstances, it istypical that the stopper forms an interference fit with the containeropening. One of the most common products to be packaged in this way iswine although other fluid products are packaged similarly.Traditionally, wine has been stored in bottles sealed with corkstoppers. Cork stoppers have been used in the wine industry for avariety of reasons most of which relate to the exceptional naturalqualities of cork as a stopper. By way of example, cork is durable,resilient, free from rotting, is sparingly permeable to gas, ispredominantly waterproof, readily compressible and easy to shape. Inmany respects, therefore, cork is a natural material to consider forsealing fluid in a container such as wine in a wine bottle.

[0003] There is always the danger when using any packaging material thatcontaminants in the material used to form the packaging will contaminatethe final product leading to a consequent drop in final product quality.This is particularly true for packaging materials that are used topackage fluid products. In many instances the performancecharacteristics of the packaging material may not properly take intoaccount the effect of sustained contact between the packaging materialand the fluid product during storage. Such an effect is exacerbated inrelation to wine where product is frequently stored for long periods oftime in the packaged state. The effect is particularly noticeable withstoppers as, in many instances, the characteristics of the material usedto produce the stopper are designed to provide ease of use of thestopper during the packaging process rather than its performance duringprolonged storage of the container. As a result, other performancecharacteristics of the stopper may be compromised.

[0004] A perfect example of how contaminants in a stopper can affectproduct quality is in the wine industry. The use of cork stoppers canlead to the development of undesirable product characteristics when usedto stopper a container containing a wine. Cork can occasionally causeoff flavours in wine and it is often the cause of musty or mouldy taintand sometimes the cause of off flavours due to oxidation. In 1994 theQuercus project was initiated by the European cork industry to reducethe occurrence of off flavours. Cork producers now follow the EuropeanCork Federation's Code of Practise to reduce taint. TCA (2,4,6Trichloroanisole) has been identified as the cause of some musty/mouldytaint. Although cork is not the only source of TCA in wine it has beenshown that some corks contain levels of TCA which are transferred towine when stored in bottles. It has also been observed that the taintscan be transferred to the wine via the vapour when the bottles are leftstanding up and the liquid does not contact the cork surface. This isdue to corks poor barrier to volatile materials, demonstrated by itsreadiness to absorb and desorb moisture vapour with changes in relativehumidity and its susceptibility to the entry of the volatiles which maybe retained and later transferred to wine.

[0005] Another aspect to be considered when packaging products iswhether the product needs to be completely sealed off from theenvironment or whether gaseous exchange is desirable. For example, withbottle storage of wine consideration of the flavour development of thewine with aging has to be taken into account. The concept of bottleaging, bottle maturation or bottle development is well known, however,little is understood or scientifically proven in this area. There issome belief that the stopper breathes and that oxygen plays a role inbottle development of the wine, although it is well proven that too muchoxygen will oxidise a wine and ruin it. There is a growing body of workthat is developing the use of micro-oxygenation to develop flavour andmature wines. Any stopper for use in the wine industry therefore shouldpreferably control the permeability of oxygen and allow in some casessome oxygen to permeate the stopper and come into contact with the wineand in other circumstances significantly block the ingress of oxygen.

[0006] A number of approaches have been developed aimed at overcomingthe problems of contamination of the product by the stopper whilst atthe same time preferably retaining control of oxygen permeability. Ithas been shown that coatings can be used to improve the performance ofcork stoppers. Waxes and paraffins may be used as coatings and appliedto corks to improve the sealing capability, for example. It has beenobserved that wax coatings also reduce the amount of liquid that soaksinto the cork over time. Silicone coatings have also been applied tocorks to improve the insertion and extraction of the cork. It is thoughtthat the silicone reduces the friction between the cork and the bottleduring both the insertion and extraction processes. Coatings of thistype are typically applied to the corks while the corks are tumbling ina rotating drum. The corks may be tumbled with a solid wax block or aliquid is squirted or otherwise sprayed onto corks. The coating is thenspread from cork to cork by the physical contact between the corkstransferring the coating and evenly distributing it. Heat may also beapplied to aid the process.

[0007] There have been several attempts to place other forms of physicalbarriers between the stopper and the wine to prevent the transmission oftainting components to the wine. Many of these attempts have worked onthe principle of applying a coating layer on the end of the stopper inthe form of a coating that is allowed to cure and dry as a film coatinglayer or in the form of a polymeric film attached to the end of thestopper. Unfortunately, the characteristics of the stoppers producedusing these techniques has been unsatisfactory. Without wishing to bebound by theory, it is thought that the problem with these approaches isthat whilst the stopper is compressible, the coating layer is typicallynot compressible. This leads to the development of imperfections in thecoating layer such as cracking, peeling, creasing and the like. Patentapplication WO 00/34140 purports to overcome these problems anddescribes a composite stopper with a body and a thick moulded elastomerplug located at the end of the stopper. The elastomer plug provides aseal to the bottle and is claimed to be a taint barrier which allegedlyprevents the wine touching the cork body of the stopper. The difficultywith this approach is that whilst it may overcome the taint problems itcreates further problems and/or has a number of disadvantages. The unitcost of each stopper is significantly higher than the unit cost of corkstoppers in general and so is undesirable from an economic standpoint.In addition elastomer plugs of the type described in this patent have ahigh transmission rate for oxygen typically meaning that the use of aplug of this type would not be expected to reduce the oxidation of thewine occurring on storage. As the exact orientation of the stopper intothe opening of the container is crucial for the performance of thestopper, expensive capping machinery is required in order to ensureadequate performance of the stopper once fitted. This markedly slowsproduction of bottled product when these stoppers are used.

[0008] It would therefore be desirable to provide stoppers forcontainers that overcome or substantially ameliorate the problemsassociated with contamination of the contents of the container by thematerials from which the stopper is made whilst preferably stillallowing for control of oxygen transmission through the stopper.

[0009] The present applicants have made a study of the prior artstoppers and have found that most of the deficiencies observed with theprior art coating techniques were caused by the radial compression ofthe stopper during insertion into an opening of a container. As thisstep could not be eliminated from the packaging process, the applicantssought ways of controlling the negative effects of this compression. Asa result of their studies, the applicants surprisingly found that theobserved problems were due not to the compression of the stopper per sebut rather were associated with the non-uniform deformation of the filmon end of the stopper during compression of the stopper. It was foundthat this was a common problem as a majority of the materials used inthe formation of stoppers do not allow for uniform deformation of thefilm when the stopper is compressed. Lack of uniformity in deformationof the film leads to the imperfections noted which, in turn, compromisethe integrity of the layer. It was found if the effect of thenon-uniform deformation of the film could be overcome, then the problemsassociated with the use of coating films could be ameliorated. As partof their studies into coated stoppers, the applicants have alsodeveloped an improved method for applying films to stoppers. This methodcan be used in the production of the stoppers of the invention. Asurprising benefit provided by the new method is that although thestopper deforms during the process, it does not produce a wrinkled filmon the stopper upon completion of the process.

SUMMARY OF THE INVENTION

[0010] In one aspect the present invention provides a container stoppercomprising a compressible body having at least one end for insertioninto an opening of a container, and a film on the end of thecompressible body for providing a protective layer between thecompressible body and the container contents; wherein at least a regionat the end of the compressible body has at least one property wherebyupon compression of the body for insertion into an opening of acontainer, said region compresses without substantially adverselyaffecting the protective layer provided by the film. There are a numberof properties of the region at the end of the compressible body that, ifpresent, will maintain the protective layer provided by the film. Oneproperty is that the region at the end of the compressible body of thestopper is substantially uniformly compressible in the plane of thesurface at the end of the compressible body.

[0011] In one aspect therefore the present invention provides acontainer stopper comprising a compressible body having at least one endfor insertion into an opening of a container, the body comprising aregion located at one end of the body presenting a surface, said regionbeing substantially uniformly compressible in the plane of the surface,and a film attached to the end of the compressible body for providing aprotective layer between the compressible body and the containercontents; whereby upon compression of the body for insertion into anopening of a container said region compresses without adverselyaffecting the protective layer provided by the film.

[0012] It has also been found that the same result can be achieved ifthe property is such that the end of the body of the stopper isconfigured in a manner such that the surface presented by the end of thebody has a smaller cross-sectional area than the cross sectional area ofthe stopper body. In yet an even further aspect therefore the presentinvention provides a container stopper comprising a compressible bodyhaving a cross sectional area and at least one end for insertion into anopening of a container; and a film attached to the end of thecompressible body for providing a protective layer between thecompressible body and the container contents; wherein at least a regionat the end of the compressible body tapers towards the end such that theend has a cross sectional area less than the cross sectional area of thebody whereby upon compression of the body for insertion into thecontainer opening the region compresses without adversely affecting theprotective layer provided by the film.

[0013] The invention further relates to packaged products where astopper of the invention is incorporated into the package. The packagedproducts are preferably fluid products such as oils, wines orcondiments.

[0014] Accordingly, in yet an even further aspect the inventioncomprises a packaged product, said packaged product comprising acontainer having an opening, a product located within said container anda container stopper inserted into said opening wherein said containerstopper comprises a compressible body having at least one end insertedinto said opening, and a film attached to the end of the compressiblebody providing a protective layer between the compressible body and theproduct in the container; wherein at least a region at the end of thecompressible body has one or more properties such that upon compressionof the body during insertion into the opening of the container saidregion compressed without adversely affecting the protective layerprovided by the film.

[0015] In yet a further aspect the invention provides a packagedproduct, said packaged product comprising a container having an opening,a product located within said container and a container stopper insertedinto said opening wherein said container stopper comprises acompressible body having a cross sectional area and at least one endinserted into said opening; and a film attached to the end of thecompressible body providing a protective layer between the compressiblebody and the product; wherein at least a region at the end of thecompressible body tapers towards the end such that the end has a crosssectional area less than the cross sectional area of the body wherebyupon compression of the body during insertion into the opening said endcompressed without adversely affecting the protective layer provided bythe film.

[0016] In an even further aspect the invention provides packagedproduct, said packaged product comprising a container having an opening,a product located within said container and a container stopper insertedinto said opening, wherein said container stopper comprises acompressible body having at least one end inserted into the opening,said body comprising a region located at one end of the body presentinga surface, said region being substantially uniformly compressible in theplane of the surface, and a film attached to the end of the compressiblebody providing a protective layer between the compressible body and theproduct; whereby upon compression of the compressible body duringinsertion into the opening of the container said region compressedwithout adversely affecting the protective layer provided by the film.

[0017] In another aspect the present invention provides a containerstopper comprising a compressible body having a cross sectional area andat least one end for insertion into an opening of a container; and afilm attached to the end of the compressible body for providing aprotective layer between the body of compressible material and thecontainer contents; wherein at least a region at the end of thecompressible body tapers towards said end such that said end has a crosssectional area less than the cross sectional area of the body.

[0018] In yet another aspect the present invention provides a containerstopper comprising a compressible body having at least one end forinsertion into an opening of a container, said body comprising a regionlocated at one end of the body presenting a surface, said region beingsubstantially uniformly compressible in the plane of the surface, and afilm attached to the end of the compressible body for providing aprotective layer between the compressible body and the containercontents.

[0019] The invention also provides a preferred method of producing acontainer stopper with a polymeric film on at least one surface thereof,preferably an end surface. This method can be used to produce thecontainer stoppers of the invention referred to previously or may beused to produce any stopper with a polymeric film on at least onesurface. The method comprises the steps of providing a containerstopper, said stopper having a compressible body having at least oneend, the end presenting a surface; providing a polymeric film, heatingthe polymeric film, and pressing the polymeric film and the surfacerelatively together so as to attach the polymeric film to the surfacewherein the heating of the film occurs either simultaneously with, orprior to, the pressing step.

DESCRIPTION OF THE FIGURES

[0020]FIG. 1. This shows a fragmentary side view of one end of apreferred stopper of the invention.

[0021]FIG. 2. This shows a side view of another preferred embodiment ofthe stopper of the invention.

[0022]FIG. 3. This shows a fragmentary longitudinal section of an end ofa preferred stopper of the invention.

[0023]FIG. 4. This shows a longitudinal view of yet a further preferredstopper.

[0024]FIG. 5. This shows a plan view of the stopper of FIG. 3 lookingdown line V-V of FIG. 3.

[0025]FIG. 6. A side view of a preferred stopper of the invention.

[0026]FIG. 7. This shows a fragmentary longitudinal view of a preferredstopper of the invention.

[0027]FIG. 8. This shows a fragmentary longitudinal view of anotherpreferred stopper of the invention.

[0028]FIG. 9. This shows a stopper located in a die prior to theapplication of a film to the end of the stopper.

[0029]FIG. 10. This shows the stopper in the die prior to the backingplates forcing film onto the two ends of the stopper.

DETAILED DESCRIPTION OF THE INVENTION

[0030] A requirement of a stopper for containers for the mass productionof a packaged product is the ability of the stopper to withstand theconditions imposed on the stopper during manufacture of the finishedproduct. One of the principle conditions typically imposed upon stoppersirrespective of the industry in which they are utilised is that thestopper is compressed at least partially prior to its insertion into anopening in a container. The stopper then typically expands once thecompression force is released leading to a tight fit of the stopper inthe container opening. The stopper usually forming an interference fitwith the opening in the container. In the wine industry bottlingoperations typically utilise high speed stoppering machines whichsubject the stoppers to large compression forces. These machinestypically utilise a number of compression jaws which radially compressthe stopper body from its normal diameter to a substantially smallerdiameter, typically about one third of the original size. A ram is thenutilised to force the stopper from the jaws of the compression machinedirectly into the opening of the container where the stopper attempts toexpand to its original diameter, thus sealing the bottle. A typical corkused in the wine industry is approximately 45 mm long with a diameter ofapproximately 24 mm. A typical internal diameter of the opening of awine bottle is about 18 mm. Significant compression of a stoppertherefore occurs in packaging of wine.

[0031] The improvements provided for stoppers disclosed in the presentinvention are applicable to any compressible stopper with a film on atleast one end. A feature of the stoppers of the present invention isthat they have a compressible body. It is preferred that the stopperbody is sufficiently compressible so that it can be compressed by atleast 5%, more preferably at least 10%, even more preferably at least15%, even more preferably at least 20%, yet even more preferably atleast 30%, even more preferably at least 40%, most preferably at least50%. A number of materials may be used in the construction of the bodyof the stoppers of the invention to achieve these compressibilityparameters. In essence, any material can be used as long as it meets thecompression criteria referred to above with those materials typicallyutilised in the manufacture of stoppers being suitable. Materials thatmay be used in the construction of the body portion of the stoppercomprise cork, agglomerated cork, micro-agglomerated cork, or 1+1 cork.Alternatively, the stopper body may be made from a polymeric material.The stopper body may comprise medium density or low density, closed cellfoamed plastic. Such foam plastics may comprise one or more polymersselected from the group consisting of plastic polymers, inert polymers,homopolymers, copolymers, terpolymers, thermoplastic elastomers, andthermoplastic olefins. It is preferred that the closed cell foam plasticmaterial comprises at least one polymer selected from the groupconsisting of polyethylenes, metallocene catalysed polyethylenes,polybutanes, polybutylenes, polyurethanes, silicones, vinyl basedresins, polyesters, ethylenic acrylic copolymers, ethylene-vinyl-acetatecopolymers, ethylene-methyl-acrylate copolymers, ethylene-butyl-acrylatecopolymers, ethylene-propylene-rubber, styrene butadiene rubber,ethylene-ethyl-acrylic copolymers, ionomers, polypropylenes, copolymersor polyporpylenes and the like. Examples of these types of materials areprovided in U.S. Pat. No. 6,355,320.

[0032] The stopper body may also be made of fibres. Fibre stopper bodiesare disclosed in U.S. Pat. No. 5,665,462 and include vegetable fibressuch as cotton, flax, sisal, linen, cellulose and jute, andanimal-derived fibres such as angora, wool, alpaca, and mixturesthereof. Synthetic fibres can also be used including cellulose acetate,cellulose triacetate, acrylics, aromines (aromatic polyamines), rayons,polyolefins (e.g. polypropylene), nylons, polyesters, polyurethanes,terylenes, teflon and mixtures thereof. Mixtures of the synthetic and/ornatural fibres may also be used.

[0033] The gross shape of the stoppers of the invention may vary greatlywith the shape of the stopper body typically being determined by theshape of the opening it is intended to be used in. As the stopper bodypreferably forms an interference fit with the opening in the containerin which it is used, it is preferred that the stopper body has at leastone end complementary in shape to the container opening. Thus, forexample, the stopper body may be rectangular, substantially cylindrical,or, indeed, any shape typically found that would be complementary to anopening of a container. The stopper body is preferably elongate. Afeature of the body of the stoppers of the invention is that they haveat least one end, preferably two ends. It is this end of the stopperbody that is ultimately inserted into the opening in the container andforms the interference fit with the opening, thus providing the stopperperformance. The most preferred stoppers of the invention are elongatestoppers having a body having two ends, the stopper body beingsubstantially cylindrical. It is preferred that the dimensions of thestopper are such that it is from 30-60 mm in length, more preferablyfrom 35-55 mm in length, even more preferably from 37-47 mm in length,most preferably about 38 mm or about 45 mm in length. The stopper bodyis preferably cylindrical with a diameter of from 18-30 mm, morepreferably from 22-26 mm, even more preferably from 23-25 mm, mostpreferably 24 mm.

[0034] The stoppers of the present invention can be used with anycontainer having an opening which can be sealed with a stopper. It ispreferred that the container is a bottle and the stopper is shaped tofit into the opening of the bottle, namely the mouth of the bottle.

[0035] The stoppers of the invention have a film on at least one end ofthe body which provides a protective layer between the body of thestopper and the contents of the container once the stopper has beeninserted into the container opening. If the stopper body only has oneend, the film is located on that end. If the stopper body has more thanone end, the film may be on only one of the ends or on a number of ends.Thus, where the stopper body has two ends, the film may be on only oneend or may be on both ends. If there are two ends it is preferred thatthe film is on both ends.

[0036] It is preferred that the film only covers the end of the body anddoes not travel beyond the end of the uncompressed body such as down thesides of the body. It is preferred, therefore, that the film completelycovers the end of the uncompressed stopper but does not travel beyondthe end of the stopper.

[0037] The improved stoppers in accordance with the invention mayutilise a number of different films. The film may be a coating layerthat has been applied as a liquid and allowed to cure or a coating layerthat has been sprayed on or otherwise applied to the stopper body. Thefilm may also be a polymeric film.

[0038] It is preferred that the film is a polymeric film, preferably amultilayer polymeric film. The polymeric film preferably comprises abarrier layer and an adhesive layer. The barrier layer preferably has alow permeability to H₂O, O₂ and CO₂ and is preferably substantiallyimpermeable to organic molecules with molecular weights greater than 40.A number of materials are known that can be used to produce barrierlayers for use in the invention stopper. Preferably, the barrier layercomprises one or more polymers or materials selected from the groupconsisting of polyethylene, polypropylene, polyethylene Terepthalate,ethylene-vinylacetate polymers, polyvinylchloride, polydivinylchloride,polyvinyldichloride, polyvinylacetates, nylon, polyvinyl alcohols,polyurethane, polyacrylonitrile, cellophane, surane, polyamines,polycarbonates, polystyrene, polyalkylene oxides, polyethylene oxides,cellulose, cellulose derivatives, and silicon polymers or metal foils. Apreferred barrier layer comprises nylon or cellulose, polyethylene andPVDC or metal or EVOH. The barrier layer may be any thickness typicallyutilised in the art. It is preferred that the barrier layer is between 1to 50 micron, preferably 2 to 40 micron, more preferably 5 to 30 micron,most preferably 10 to 30 micron.

[0039] The film also preferably includes an adhesive layer. The adhesivelayer may be added to the film prior to application to the stopper bodyby way of a spray or may be laminated onto the film prior to applicationof the film to the stopper body. Suitable adhesive layers include thoseselected from the group consisting of hot melt adhesives or heatactivated adhesives. Suitable adhesives therefore include polyethylenevinyl acetate, polyamides, acrylics, methyl methacrylate based polymers,starch based adhesives, carbohydrate based adhesives, protein basedadhesives, animal glues, rubbers, silicones, epoxy resins,melamine-formaldehyde based adhesives, unsaturated polyesters,urea-formaldehyde resins, resorcinols, phenolic adhesives, urethanes,polysulfides, polyvinyl and ethylene vinyl acetate polymers.Particularly preferred adhesive layers are ethylene vinyl acetatepolymers.

[0040] The adhesive layer preferably has a thickness of between 0.1 to15 micron, more preferably 4 to 15 micron, most preferably 10 to 15micron. If a heat activated adhesive is used, it preferably has anactivation temperature greater than 30° C., more preferably greater than50° C., most preferably greater than 80° C.

[0041] The stoppers of the invention have at least a region at an end ofthe compressible body which has at least one property such that uponcompression of the body for insertion into an opening of a container,the region compresses without substantially adversely affecting theprotective layer provided by the film. If the body has more than oneend, a region of this type may be located at either end or there may bea region located at each end. The region may be integral with theremainder of the stopper body or may be attached to the remainder of thestopper body to form a composite stopper body. There are a number ofproperties the region may have which will provide the desired result.

[0042] One property of the region is for it to taper toward the end atwhich it is located in such a way that the end of the stopper has asurface area that is less than the cross-sectional area of the remainderof the stopper body. In one preferred embodiment therefore, the propertyof the end of the stopper that provides an improved stopper is that atleast a portion of the region at the end of the stopper tapers towardsthe end of the compressible body. The taper is such that thecross-sectional area of the end is less than the cross-sectional area ofthe body. It is found that only minor tapers are required as only minorreductions in the cross-sectional area of the end of the stopper bodyare required to maintain the protective integrity of the film. The taperis preferably such that the cross-sectional area of the end is less than98% of the cross-sectional area of the body, more preferably less than96%, even more preferably less than 92%, more preferably less than 85%,even more preferably less than 80%, yet more preferably less than 75%,most preferably less than 70% of the cross-sectional area of the body.Particularly preferred ranges of the taper are such that thecross-sectional area end of the stopper is between 65% and 85% of thecross-sectional area of the body. Without wishing to be bound by theory,it is though that such a reduction allows for the control of thedeformation of the film on compression of the body.

[0043] It has been found that any of a number of different tapers can beused to provide the desired performance characteristics. For example,the taper may be a uniform or a non-uniform taper. By uniform taper itis meant that the reduction in thickness of the stopper body is constantas it approaches the end. It is preferred, however, that the taper is auniform taper as this is most easily mass produced and therefore themost desirable economically. At least in principle, however, any type oftaper may be used. Thus, the side of the body as it tapers may bestraight or curved in shape. It is preferred that the taper not be soextensive that the end of the body on which the film is located becomesmaller than the opening of the bottle it is intended to seal. If thisoccurs, there is a compromise of the effectiveness of the protectivelayer provided by the film. It is preferred that the taper only continuefor a minor portion of the stopper body. It is preferred that the taperoccurs on less than 30% of the stopper body, even more preferably lessthan 20% of the stopper body, more preferably less than 10%, yet evenmore preferably less than 5%, even more preferably on less than 2%, mostpreferably less than 1% of the stopper body. It is found that the taperis equally effective if it is located essentially only at the endalthough in principle, the taper may traverse almost the entire lengthof the stopper body. One preferred method of forming the taper of thestopper body is to produce a stopper and then chamfer the end to achievea tapered stopper body. This step of chamfering the stopper body mayoccur either before or after the attachment of a film to the end of thebody. The following tables (1) and (2) list the relative surface areawith different size chamfers for a number of different size stopper bodydiameters. TABLE 1 Total Chamfer Size (mm) Cork 0 0.2 0.5 1 Dia (mm) SaSa Ra Sa Ra Sa Ra 22 380.13 373.25 0.982 363.05 0.955 346.46 0.911 23415.48 408.28 0.983 397.61 0.956 380.13 0.914 23.5 433.74 426.38 0.983415.48 0.957 397.61 0.916 24 452.39 444.88 0.983 433.74 0.958 415.480.918 24.5 471.44 463.77 0.984 452.39 0.959 433.74 0.920 25 490.87483.05 0.984 471.44 0.960 452.39 0.921 30 706.86 697.47 0.987 683.490.966 660.52 0.934

[0044] TABLE 2 Total Chamfer Size (mm) Cork 0 2 3 4 Dia (mm) Sa Sa Ra SaRa Sa Ra 22 380.13 314.16 0.826 285.53 0.745 254.47 0.669 23 415.48346.36 0.833 314.16 0.756 283.53 0.682 23.5 433.74 363.05 0.837 330.060.760 298.65 0.688 24 452.39 380.13 0.840 346.36 0.765 314.16 0.694 24.5471.44 397.61 0.843 363.05 0.770 330.06 0.700 25 490.87 415.48 0.846380.13 0.774 346.36 0.705 30 706.86 615.75 0.871 572.56 0.81 530.930.751

[0045] In the tables, total chamfer size indicates the total amount ofchamfer when the chamfer at the two sides of the body are addedtogether. Thus, with a chamfer size of 2, there has been approximately 1mm of stopper body removed from each side.

[0046] Sa=Surface area (mm²)

[0047] Ra=Surface area of end of chamfered cork/cross-sectional area ofcork

[0048] It is preferred that the stopper body has two ends. It isparticularly preferred when using the property of a tapered body toproduce the improved stoppers that where there are two ends, then bothof the ends of the compressible body are tapered. If this occurs, it ispreferred that both ends are tapered in the same manner and to the sameextent. The advantage of this is that stoppers of this type can be usedin conventional bottling machines which do not discriminate between thetwo ends of the stopper. Therefore, using stoppers with two ends withsimilar tapers on the ends allows the stopper to perform the desiredfunction irrespective of the end of the stopper selected by the machinefor insertion into the bottle.

[0049] In addition to machining a stopper body (either before or afterapplication of a film) to achieve the taper discussed above, the tapermay also be achieved by attaching a pre-tapered layer or disc to one ormore ends of a stopper body to produce a composite stopper body with atapered region at least, one end. Whilst this technique can be utilised,it is not preferred as it is not cost-effective as these stoppers thenbecome expensive to produce relative to the machining technique. Aswould be clear to a skilled addressee, a combination of these techniquesmay be used. Of course, with stopper bodies that are produced bymoulding processes, the taper may be built into the mould leading to aformed stopper having a taper.

[0050] Another property of the region at the end of the body of thestopper that can be exploited to achieve the desired results, is toprovide a stopper with a region at one end of the body where the regionis substantially uniformly compressible in the plane of the surfacedefined by that region. By substantially uniformly compressible as usedherein, it is meant that when the region is subjected to a defined forcein a first direction, the amount of deformation in that direction issubstantially the same as the amount of deformation observed if theregion was subjected to a similar force in a different direction.Alternatively, if the end of the region does not present a planarsurface, it is preferred that the region is substantially uniformlycompressible in a plane perpendicular to the longitudinal axis of theopening of the container that the stopper is intended to seal. It isfound if the region at the end of the body portion is substantiallyuniformly compressible in this plane, then the deformation properties ofa film coated on the region are such that the compression does notcompromise the efficacy of the protective layer formed by the film.Whilst there will almost always be some degradation of the filmproperties on compression, these can be minimised within acceptablebounds.

[0051] There are many ways of achieving substantially uniformcompressibility of the region at the end of the stopper. One preferredmethod is to ensure that the stopper body is made from a uniformlycompressible material. When using natural cork, for example, it isdifficult to achieve uniform compressibility as natural cork istypically cut from the tree in a manner such that the growth rings ofthe tree occur throughout the cork. Use of these materials typically donot allow for the uniform compressibility of the cork material as thegrowth rings produce zones of different compressibility. If, however,the stopper body comprises cork cut from cork trees in such a mannerthat the cork is cut transverse to the typical direction of cutting thecork stopper from the tree, improved uniformity can be achieved.Agglomerate corks are produced by extruding a mixture of adhesive andcork granules through a heated die to produce a rod which is cut andground to a cylindrical stopper. During granule feed from the hopper andthe extrusion process, different sized granules preferentially positionthemselves so that the final cork is not entirely homogenous. Inaddition, each individual granule has different compression propertiesand is oriented differently. As a result, agglomerated corks are moreuniformly deformed under radial compression than natural cork stopperscut in the usual direction, however, they are not precisely uniformduring radial compression. Therefore, with some films with particularstiffness and adhesion properties, agglomerated cork may provide thedegree of compression uniformity required.

[0052] Another way of achieving the same result is to attach a materialthat is substantially uniform compressible in the plane of the surfacesuch as a disc or layer on the end of the body to form a compositestopper body having a region at one end that is substantially uniformlycompressible in the plane of the surface defined by the region. Whenusing a disc or layer of uniformly compressible material attached to thestopper to form a composite stopper body it is found that the importantcharacteristic is the compression behaviour of the disc or layer, notthe entire stopper body per se. Thus, as long as the compressioncharacteristics of the disc or layer are acceptable, then a lack ofuniformity in the compression characteristics of the remainder of thestopper body will be irrelevant. It is preferred that if the stopper hastwo ends, then a region of uniformly compressible material is located ateach end. There are any number of uniformly compressible materials thatcould be utilised in the formation of the disc or layer discussed aboveand these would be clear to a skilled addressee. In principle, anysubstantially uniformly compressible material could be used. A skilledworker in the art would be able to quickly determine whether a materialwas uniformly compressible by the use of simple compression tests.

[0053] Of course a number of properties of the region at the end of thestopper body may act in concert to produce the improved stoppers. Thus,in a particularly preferred embodiment, at least a region at the end ofthe stopper body tapers toward said end and is also uniformlycompressible in the plane of the surface at the end of the stopper bodypresented by the region. If the stopper has two ends it is preferredthat this occurs at each end.

[0054] The invention also relates to products packaged using theinvention stoppers. The preferred packaged products of the invention arefluid products and, in particular, oils, wines and vinegar. Thepreferred containers for use with the packaged products of the inventionare bottles, preferably glass bottles.

[0055] In a further embodiment, the invention provides a method ofproducing a container stopper with a polymeric film on at least onesurface thereof for protecting said surface said method comprising thesteps of

[0056] (a) providing a container stopper, said stopper having acompressible body having at least one end, said end presenting asurface;

[0057] (b) providing a polymeric film,

[0058] (c) heating the polymeric film, and

[0059] (d) pressing the polymeric film and the surface relativelytogether so as to attach the film to the surface, wherein the step ofheating the film occurs either simultaneously with, or prior to, thepressing step.

[0060] It is preferred that the step of providing a container stoppercomprises positioning a container stopper in a stopper holding means. Apreferred stopper holding means is a die having an internal cavity forreceiving the stopper. The preferred internal dimensions of the cavityranges from 4 mm smaller to 4 mm larger than the external dimensions ofthe stopper to be subjected to the process. It is particularly preferredthat the internal dimensions of the cavity match the external dimensionsof the stopper. A smaller dimension on the cavity allows for the stopperto be firmly held in position throughout the process while a largerdimension allows the film to overhang the end of the stopper ifrequired. The preferred die has a length less than the length of thestopper such that at least a portion of the stopper protrudes from thecavity in the die. The form of the die will depend on the shape of thestopper to be subjected to the method. It is preferred that the shape ofthe internal cavity of the die is complementary to the shape of thestopper body. The die can be configured so only one end of the stopperis subjected to the method (in these cases one end of the die has ablank to prevent the stopper from protruding from both ends of thecavity) or such that two ends of a stopper can be treated simultaneouslyin which case both ends of the die are open and the die is substantiallytubular to allow the stopper to protrude from each open end.

[0061] The type of stoppers that can be subjected to the process are thestoppers described hereinbefore. The stoppers that may be subjected tothe process may have a film on at least a surface such as an end or may,prior to subjecting to the process, be devoid of film. The films thatcan be used in the method are those polymeric films describedhereinbefore.

[0062] Once the stopper has been provided in the desired orientation forapplication of a polymeric film, a suitable polymeric film is provided.In a preferred embodiment, the polymeric film is provided as acontinuous polymeric film, spooled between two film holding elements.The polymeric film typically spools between these two film holdingelements. The film holding elements are preferably arranged so as to beable to cooperate to advance the film in either direction as required.The film holding elements are preferably arranged or oriented such thatthat one surface of the polymeric film is in substantially the sameplane as the surface of the end of the stopper to which the polymericfilm is intended to be attached. It is preferred that the polymeric filmcomprises an adhesive layer as an outer layer and that the orientationof the film is such that the side of the film opposing the end of thestopper has the adhesive layer as the outer layer.

[0063] In the process of the invention the film is heated prior to orsimultaneously with the pressing step. The heating may be achieved in anumber of ways including pre-heating of the film prior to the pressingstep by means of a heated blast of air or other gas blown over thesurface of the film. It is also possible for the film to be passedthrough a heating chamber or heated zone prior to the pressing step inwhich case heat is transferred to the film in the heating chamber orheating zone. The heating can also be applied by heating the die holdingthe stopper or, alternatively, the backing plate that forces the film onto the stopper can be at an elevated temperature such that heat istransferred to the film on pressing. It is preferred that the heating issuch that the film is heated to at a temperature sufficient to soften,melt or activate the outer layer of the film typically at least 40° C.,preferably at least 80° C., more preferably at least 120° C.

[0064] In the process of the invention, the film and the surface of thestopper are pressed relatively together so as to attach the film to thesurface. There are a number of ways in which the relative pressingtogether of the polymeric film and the stopper surface can be achieved.Thus, for example, the polymeric film can be held in place and thestopper surface pressed against the film. If this is the case, a backingplate is typically utilised to ensure the film does not deform away fromthe stopper on pressing. Alternatively, both film and die may moverelative to each other to press the stopper surface and polymeric filmtogether. It is preferred, however, that the stopper is held relativelysecurely and the film pressed onto the surface of the stopper by way ofa moveable backing plate. It is preferred that the backing platecooperates with the die in which the stopper is held during pressing tocut the film such that the film is only located on the surface of theend of the stopper. It is preferred that the pressing is carried outwith sufficient force to compress the compressible body of the stopperby at least 0.5%, more preferably at least 1%, more preferably at least2%, yet even more preferably at least 3%, even more preferably at least10%, most preferably at least 15%. The pressing step may in theory becarried out for any period of time. It is preferred, however, that it iscarried out for between 0.1 to 60 seconds, more preferably 0.1 to 15seconds, most preferably 0.1 to 5 seconds. On completion of pressing theforce is removed by removing the backing plate.

[0065] The process of invention can occur in such a way that only oneend of the stopper is treated or, alternatively, both ends of thestopper can be simultaneously treated by the process described above. Inthis manner, two backing plates are utilised with two polymeric films.Upon completion of the pressing step, the backing plate or plates arereleased so as to reduce pressure. If the process is run as a continuousprocess, the film is then advanced, a further stopper is provided andthe process repeated. One way of achieving this is to have a number ofdies arranged on an axle or slide wherein, after treatment of onestopper is complete, the axle or slide advances to a further position topresent a new stopper to be treated and the treated stopper is punchedout with a ram and replaced. This allows the process to be relativelyefficient and time and cost-effective and can therefore be run as acontinuous process.

[0066] The above description provides an overview of the inventivestopper and process of the invention. The invention will now be furtherdescribed with reference to the accompanying drawings.

[0067] A fragmentary view of one end of the stopper is shown in FIG. 1.There is a film (1) on the end of the stopper body and a region (2) atthe end of the stopper body that is substantially uniformly compressiblein the plane of the surface presented by the region at the end of thestopper body.

[0068]FIG. 2 shows a view of yet a further preferred stopper of theinvention with film (1) located on each end. There are regions (2) ateach end of the stopper, each of the regions being substantiallyuniformly compressible in the plane of the surface at the end of thestopper presented by the region. In this embodiment this substantiallyuniformly compressible region is located at each end of the stopper andallows for use of the stopper in automated stoppering machines.

[0069]FIG. 3 shows a cross-sectional fragmentary view of yet a furtherpreferred stopper of the invention. The stopper in FIG. 3 incorporates ataper. There is a film (1) located on the end surface of the stopperbody (3) with the taper at the end of the stopper body indicated bytapering sides (4) and (5), being such that the cross-sectional area ofthe surface of the end of the stopper on which the film (1) is located,being less than the cross-sectional area of the stopper body.

[0070]FIG. 4 is a cross-sectional side view of a preferred stopper ofthe invention with a taper at both ends. A film (1) is located on eachend of the stopper body (3). Each end of the stopper body tapers asshown such that the surface area of the ends covered by the film (1) isless than the cross-sectional area of the stopper.

[0071]FIG. 5 shows a plan view looking down line V-V shown in FIG. 3.The outer ring (6) represents the sides of the stopper body and theinner ring (7) represents the surface at the end of the stopper bodyafter the taper.

[0072]FIG. 6 represents a particularly preferred embodiment of theinvention. This embodiment demonstrates the combined effect of a taperand a substantially uniformly compressible region at the end of thebody. The stopper has a stopper body (3) with a film (1) located on eachend. At each end of the stopper body, there are substantially uniformlycompressible regions (2) with at least a portion of each of the regionsbeing tapered such that each of the ends has a cross-sectional area thatis less than the cross-sectional area of the body. The tapered bodysides (4) and (5) are clearly shown.

[0073]FIGS. 7 and 8 show different preferred tapers at the ends of thestopper body. Thus, in FIG. 7 there is a stopper body (3) with a film(1) on the end thereof. There are tapered sides (4) and (5). The extentof the taper in FIG. 7 is less than the taper shown in FIGS. 3 and 4 andshows how the angle of the taper can be varied.

[0074] In FIG. 8 there is a stopper body (3) with a film (1) located onone end. In this case, the edges (8) and (9) are tapered such that theyare rounded with the end of the stopper having a lower cross-sectionalarea than the cross-sectional area of the stopper body.

[0075]FIG. 9 shows a stopper body (3) located with a stopper holdingmeans. The two ends of the stopper protrude from the ends of the stopperholding means.

[0076]FIG. 10 is a schematic of the process of the invention immediatelyprior to the pressing step. There is a stopper holding means (11) withtwo ends of a stopper (12) and (13) protruding therefrom as in FIG. 9.There are two polymeric films (14) and (15) provided as part of acontinuous film and backing plates (16) and (17) which are arranged topress the film onto the ends of the stopper. After the compression iscomplete, the backing plates (16) and (17) are released and the filmadvances in the direction shown to treat a further stopper. As shown,the polymeric films include voids (18) and (19) showing where polymericfilm has been punched out of the continuous film during treatment of theprevious stopper.

[0077] The present invention will now be more fully described withreference to the accompanying example. It should be understood, however,that the description following is illustrative only and should not betaken in any way as a restriction on the generality of the inventiondescribed above.

EXAMPLE 1

[0078] Coating Films Preparation

[0079] A 20 micron multilayer film containing a 15 micron high densitypolyethylene layer with a 5 micron ethylene-vinyl acetate copolymer(EVA) layer was produce using conventional coextrusion blown filmequipment.

[0080] A 40 micron multilayer film containing layers ofEVA/PE/PVDC/Nylon was produced by extrusion and laminating usingconventional techniques.

[0081] Producing Cork Stoppers with End Film Coating

[0082] A cutting tool was manufactured 26 mm in diameter with aninternal cylindrical cavity 42 mm deep. Corks of 24 mm diameter, 45 mmlength were taken from a batch of commercial corks. The ends the corkswere coated with both the EVA/PE/PVDC/Nylon film and polyethylene/EVAfilm in one step using the tool described by pressing the cork onto aheated backing plate (125° C.) with the cork inside the cutting tool,the films held between the cork and the backing plate. Each of the corkswas then measured to determine the ratio of the diameter of the filmversus the diameter of the cork.${\therefore R} = \frac{{Diameter}\quad {of}\quad {the}\quad {film}}{{Diameter}\quad {of}\quad {the}\quad {cork}\quad {body}}$

[0083] Thus, where the film was located only on the end of the stopperbody and completely covering it R=1.00. Where there was an overlay offilm over the end of the stopper R=1.08.

[0084] Chamfering the Coated Corks to Reduce the R Value

[0085] A number of the coated corks were then chamfered by rotating theedges on sandpaper to produce tapered corks. In these cases, thecross-sectional area of the surface of the stopper was less than thecross-sectional area of the body of the stopper. R values of 0.92, 0.83,0.79 and 0.75 were thereby produced.

[0086] Wax and Silicone Coating

[0087] The corks were waxed and silicone coated by tumbling 100 corkswith solid paraffin wax for 20 minutes and then with squirting 1 ml of7004 CAF silicone on the corks and tumbling for a further 30 minutes.This was done to improve insertion of the corks into the bottle neck.

[0088] The Effect of R and the Ratio of the Surface Area of the End ofthe Stopper Value on Gas Transmission

[0089] The amount of air that enters the bottle at bottling can be seenby applying a vacuum at bottling and inverting the bottle and watchingthe air bubbles that stream into the bottle. (0—no streaming; 5—maximumamount of streaming) Quantity of bubbles R value Area Ra entering bottle1.08 531 1.17 5 1.0 453 1 4 0.92 380 0.84 3.5 0.83 314 0.69 1 0.79 2840.63 0 0.75 255 0.56 1.5

[0090] It is clear that oxygen transmission is at optimal levels whenthe stopper body has a taper. As would be clear to a skilled addressee,it would be expected that the optimal taper will vary according to theproperties of the compressible material of the stopper, the propertiesof the coating film and the dimensions of the opening into which it isultimately inserted.

EXAMPLE 2

[0091] Cork Travel Test

[0092] Another test that distinguishes the sealing ability of corks isknown as the Travel Test. This test measures the number of bottles thatallow wine to travel up between the cork and the bottle neck. Thedistance the wine travels is recorded. The test is accelerated by layingthe bottles down and heating them to 30° C. for a week. The heatincreases the pressure the wine exerts on the seal. With film coatedcorks travel is usually associated with wine soaking underneath thefilm. The degree of this under soak can also be measured.

[0093] Four coated corks were tested by this method. Some of the corkswere altered by gluing a 4 mm thick transverse cut cork disk onto theend of the cork prior to coating with a polymer film. Each cork type was24 mm diameter by 44 mm long in their completed form.

[0094] Transverse cut means the disk was cut in a directionperpendicular to the direction cork for wine stoppers is usually cut.The end face of the disk originally faced into or away from the treetrunk. Therefore the lenticels (or air holes that originally allowed airto pass through the bark to the tree) pass from one face of the disk tothe other. Natural cork stoppers are not cut in this direction becausethe wine can travel up through the lenticels from the inside end of thecork to the outside end. Usually, the end face of a cork stopperoriginally faced either the ground or the sky and the lenticels passacross the body of the cork. When compressed radially the transverse cutdisk, although not precisely uniform, has a much greater uniformity ofdeformation than the usually cut cork stopper. Meaning that when a forceis applied at the edge of the disk towards the disk's centre, thedeformation is similar to the deformation achieved when a similar forceis applied to another point on the edge of the disk and directed towardsthe centre of the disk. When cork is cut in the usual way with the endsoriginally pointing to the ground and sky, the deformation uniformity ispoor due to growth rings and the shape and orientation of the unit cellsmaking up the cork.

[0095] The four cork types were

[0096] 1. Straight natural cork

[0097] 2. Straight natural cork with 2 mm diameter chamfer

[0098] 3. Cork with a transverse cut cork disk glued on end

[0099] 4. Cork with a transverse cut cork disk glued on end with a 2 mmchamfer.

[0100] Prior to any chamfering being done, each of the corks was coatedwith a 60 micron film consisting of the layersEVA/PE/PVDC/Nylon/EVA/HDPE by heating and pressing the film onto thecork at 125° C. as described in example 1. Prior to bottling, the corkswere coated with wax and silicone by tumbling for 60 minutes withapproximately 0.0087 g wax and 0.0064 g of silicone per cork. The traveland under film soak results for six repeats of each cork after storageat 30° C. for three weeks were as shown in the following table. % withsoak % travel % with no under film Cork % without % travel less greaterthan soak under greater than No travel than 5 mm 5 mm the film 30% ofarea 1 0 50 50 0 83 2 0 100 0 33 33 3 67 33 0 83 13 4 100 0 0 100 0

[0101] It is clear from the above that stoppers with a chamfered endhave improved performance characteristics as opposed to natural cork. Itis also clear that the use of a substantially uniformly compressibleregion or layer on the end of the stopper body also improves stopperperformance. A combination of these features is clearly superior.

The claims defining the invention are as follows:
 1. A container stoppercomprising a compressible body having at least one end for insertioninto an opening of a container, and a film on the end of thecompressible body for providing a protective layer between thecompressible body and the container contents; wherein at least a regionat the end of the compressible body has at least one property wherebyupon compression of the body for insertion into an opening of acontainer said region compresses without substantially adverselyaffecting the protective layer provided by the film.
 2. A containerstopper according to claim 1, the compressible body having a crosssectional area, wherein the property is that at least a portion of theregion tapers towards the end of the compressible body such that the endhas a cross sectional area that is less than the cross sectional area ofthe body.
 3. A container stopper according to claim 2 wherein the endhas a cross sectional area that is less than 96% of the cross sectionalarea of the body.
 4. A container stopper according to claim 3 whereinthe cross sectional area of the end is less then 85% of the crosssectional area of the body.
 5. A container stopper according to claim 2wherein the film is a multilayer film comprising a barrier layer and anadhesive layer wherein the barrier layer comprises at least one polymeror material selected from the group consisting of polyethylene,polypropylene, polyethylene terephthalate, ethylene-vinyl acetatecopolymer, polyvinyl chloride, polydivinyl chloride, polyvinyldichloride, polyvinyl acetate, nylon, ethylene-vinyl alcohol copolymer,polycarbonates, polystyrene, polyalkylene oxide polymers, polyethyleneoxide polymers, cellulose, cellulose derivatives, silicon polymers andmetal; and wherein the adhesive layer comprises at least one of hot meltadhesives or heat activated adhesives selected from the group consistingof ethylene vinyl acetate, polyamides, acrylics, methyl methacrylatebased adhesives, starch based adhesives, carbohydrate based adhesives,protein based adhesives, animal glues, rubbers, silicones, epoxy resins,melamine-formaldehyde based adhesives, unsaturated polyesters,urea-formaldehyde resins, resorcinols, phenolic adhesives, urethanes,polysulfides and polyvinyls.
 6. A container stopper according to claim 2wherein the compressible body has two ends, film being attached to eachof the ends, the compressible body having a region located at each ofthe ends, at least a portion of each region tapering towards the end ofthe compressible body at which it is located such that each of the endshas a cross sectional area that is less than the cross sectional area ofthe body.
 7. A container stopper according to claim 2 wherein the bodyis substantially cylindrical.
 8. A container stopper according to claim2 wherein the region presents a surface at the end of the body, at leasta portion of the region being substantially uniformly compressible inthe plane of the surface.
 9. A container stopper according to claim 2wherein at least a portion of the body comprises cork, agglomeratedcork, micro-agglomerated cork or synthetic cork.
 10. A container stopperaccording to claim 1 wherein the region located at the end of the bodypresents a surface at the end of the body, wherein said property is thatat least a portion of the region is substantially uniformly compressiblein the plane of the surface.
 11. A container stopper according to claim13 wherein the film is a multilayer film comprising a barrier layer andan adhesive layer, wherein the barrier layer comprises a polymer ormaterial selected from the group consisting of polyethylene,polypropylene, polyethylene terephthalate, ethylene-vinyl acetatecopolymers, polyvinyl chloride, polydivinyl chloride, polyvinyldichloride, polyvinyl acetate, nylon, ethylene-vinyl alcohol copolymers,polycarbonates, polystyrene, polyalkylene oxide polymers, polyethyleneoxide polymers, cellulose, cellulose derivatives, silicon polymers andmetal; and wherein the adhesive layer comprises at least one hot meltadhesive or heat activated adhesives selected from the group consistingof ethylene vinyl acetate polymers, polyamides, acrylics, methylmethacrylate based adhesives, starch based adhesives, carbohydrate basedadhesives, protein based adhesives, animal glues, rubbers, silicones,epoxy resins, melamine-formaldehyde based adhesives, unsaturatedpolyesters, urea-formaldehyde adhesives, resorcinols, phenolic resins,urethanes, polysulfides and polyvinyls.
 12. A container stopperaccording to claim 10 wherein the compressible body has at least twoends, film being attached to each of the ends, the compressible bodyhaving a region located at each of the ends, each region presenting asurface at the end of the body at which it is located, at least aportion of each region being substantially uniformly compressible in theplane of the surface presented by the region.
 13. A container stopperaccording to claim 10 wherein said body is substantially cylindrical.14. A container stopper according to claim 10 wherein the body has across sectional area, at least a portion of the region tapering towardsthe end of the body of compressible material such that the end has across sectional area less than the cross sectional area of the body. 15.A stopper according to claim 14 wherein each region tapers towards theend of the compressible body at which it is located such that each endhas a cross sectional area that is less than the cross sectional area ofthe body.
 16. A container stopper comprising a compressible body havinga cross sectional area and at least one end for insertion into anopening of a container; and a film attached to the end of thecompressible body for providing a protective layer between thecompressible body and the container contents; wherein at least a regionat the end of the compressible body tapers towards the end such that theend has a cross sectional area less than the cross sectional area of thebody whereby upon compression of the body for insertion into thecontainer opening the region compresses without adversely affecting theprotective layer provided by the film.
 17. A container stopper accordingto claim 16 wherein the end has a cross sectional area that is less than96% of the cross sectional area of the body.
 18. A container stopperaccording to claim 17 wherein the end has a cross sectional area that isless than 85% of the cross sectional area of the body.
 19. A containerstopper according to claim 16 wherein the compressible body has at leasttwo ends, film being attached to each of the ends, the compressible bodyhaving a region located at each of the ends, each region taperingtowards the end of the compressible body at which it is located suchthat each of the ends has a cross sectional area that is less than thecross sectional area of the body.
 20. A container stopper according toclaim 16 wherein the body is substantially cylindrical.
 21. A containerstopper according to claim 16 wherein at least a portion of the bodycomprises cork, agglomerated cork, micro-agglomerated cork or syntheticcork.
 22. A container stopper according to claim 16 wherein the regionpresents a surface at the end of the body, at least a portion of theregion being substantially uniformly compressible in the plane of thesurface.
 23. A container stopper comprising a compressible body havingat least one end for insertion into an opening of a container, said bodycomprising a region located at one end of the body presenting a surface,said region being substantially uniformly compressible in the plane ofthe surface, and a film attached to the end of the compressible body forproviding a protective layer between the compressible body and thecontainer contents; whereby upon compression of the body for insertioninto an opening of a container said region compresses without adverselyaffecting the protective layer provided by the film.
 24. A containerstopper according to claim 23 wherein the film is a multi-layer film,said multilayer film comprising at least one barrier layer and at leastone adhesive layer.
 25. A container stopper according to claim 23wherein said body of compressible material has at least two ends, filmbeing attached to each of the ends, the body of compressible materialhaving a region located at each of the ends, each region presenting asurface, each region being substantially uniformly compressible in theplane of the surface they present.
 26. A container stopper according toclaim 25 wherein the body of compressible material has a cross sectionalarea, the body tapering towards at least one end such that the crosssectional area of at least one end is less than the cross-sectional areaof the compressible body.
 27. A method of producing a container stopperwith a film on at least one surface thereof for protecting said surfacesaid method comprising the steps of (a) providing a container stopper,said stopper having a compressible body having at least one end, saidend presenting a surface; (b) providing a polymeric film, (c) heatingthe polymeric film, and (d) pressing the polymeric film and the surfacerelatively together so as to attach the film to the surface, wherein thestep of heating the film occurs either simultaneously with or prior tothe pressing step.
 28. A method according to claim 27 wherein the stepof providing a film comprises providing a multilayer film comprising abarrier layer and an adhesive layer.
 29. A method according to claim 28wherein said adhesive layer is an external layer of the film and thefilm is provided in an orientation such that during step (d) theadhesive layer contacts the surface.
 30. A method according to claim 27wherein the film is heated to a temperature greater than the softening,melting or activation temperature of the outer layer of the polymericfilm.
 31. A method according to claim 27 wherein during step (d) thepressing is sufficient to compress the compressible body of the stopperby at least 5%.
 32. A method according to claim 27 wherein pressingcontinues for a period of between 0.1 to 5 seconds.
 33. A methodaccording to claim 27 wherein the film is provided as a continuous film.34. A packaged product, said packaged product comprising, (a) acontainer having an opening, (b) a product located within saidcontainer, (c) a container stopper inserted into said opening whereinsaid container stopper comprises a compressible body having at least oneend inserted into said opening, and a film attached to the end of thecompressible body providing a protective layer between the compressiblebody and the product in the container; wherein at least a region at theend of the compressible body has one or more properties such that uponcompression of the body during insertion into the opening of thecontainer said region compressed without adversely affecting theprotective layer provided by the film.
 35. A packaged product, saidpackaged product comprising, (a) a container having an opening, (b) aproduct located within said container, (c) a container stopper insertedinto said opening wherein said container stopper comprises acompressible body having a cross sectional area and at least one endinserted into said opening; and a film attached to the end of thecompressible body providing a protective layer between the compressiblebody and the product; wherein at least a region at the end of thecompressible body tapers towards the end such that the end has a crosssectional area less than the cross sectional area of the body wherebyupon compression of the body during insertion into the opening said endcompressed without adversely affecting the protective layer provided bythe film.
 36. A packaged product, said packaged product comprising, (a)a container having an opening, (b) a product located within saidcontainer, (c) a container stopper inserted into said opening whereinsaid container stopper comprises a compressible body having at least oneend inserted into the opening, said body comprising a region located atone end of the body presenting a surface, said region beingsubstantially uniformly compressible in the plane of the surface, and afilm attached to the end of the compressible body providing a protectivelayer between the compressible body and the product; whereby uponcompression of the body during insertion into the opening of thecontainer said region compressed without adversely affecting theprotective layer provided by the film.
 37. A container stoppercomprising a compressible body having a cross sectional area and atleast one end for insertion into an opening of a container; and a filmattached to the end of the compressible body for providing a protectivelayer between the body of compressible material and the containercontents; wherein at least a region at the end of the compressible bodytapers towards said end such that said end has a cross sectional arealess than the cross sectional area of the body.
 38. A container stoppercomprising a compressible body having at least one end for insertioninto an opening of a container, said body comprising a region located atone end of the body presenting a surface, said region beingsubstantially uniformly compressible in the plane of the surface, and afilm attached to the end of the compressible body for providing aprotective layer between the compressible body and the containercontents.